The development of the liquid-cooled Continental Hyper high-horsepower engine began in 1932. It featured cylinders with "spherical" combustion chambers and sodium cooled exhaust valves. An upright V-12 engine was planned, but emphasis was later changed to an inverted V-12 engine for pursuit planes. Continental built the inverted V engine in 1938 and successfully tested it in 1939. In 1943 the 1,600-hp IV-1430 engine, later redesignated the XI-1430, was tested extensively in the Lockheed XP-49, a modified version of the P-38 Lightning. In 1944 it was also tested in the McDonnell XP-67. Only 23 I-1430 series engines were delivered. Although more powerful and lighter than the nearest competitor, the engine was not produced because tooling capacity for large scale production was not available.

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